1. Field of the Disclosure
The present disclosure relates to a ridge-waveguide semiconductor laser diode (LD), and more particularly, to a ridge-waveguide semiconductor LD configured such that a current is laterally injected through side surfaces of a ridge portion.
2. Description of the Related Art
Semiconductor laser diodes (LDs) are widely used for transmitting, recording, and reading data in communication devices, such as optical communication devices, or in electronic devices, such as compact disk players (CDPs) or digital video disk players (DVDPs).
As the use of the semiconductor LDs has increased, semiconductor LDs having a low critical current value and a ridge portion that suppresses multiple transverse mode oscillation have been developed. The ridge portion is formed by upwardly protruding a p-type cladding layer and a p-type contact layer, and a current (holes) is vertically injected down into the ridge portion. However, the vertical current injection has a drawback in that high power is consumed and heat is generated due to the high resistance of a region doped with an impurity, such as magnesium (Mg), when the current (holes) passes through p-type semiconductor layers including the p type cladding layer and a p-type waveguide layer.